pests?

- Anything humans believe it to be UNDESIRABLE (looks, competing for resources, spread of disease)

WHAT ARE PESTS????

What Are Pesticides

- Chemicals used to kill

pests.

1. FIRST-GENERATION pesticides

- Where it comes from: Naturally found in the environment

- Examples: Arsenic and lead

- Problem: Found to kill animals

2. SECOND-GENERATION pesticides

- Where it comes from: Man made

- Examples:DDT used to kill insects

- Problem: Binds to our fat and stays there

forever

Newer pesticides

- Binds to water in animals when

ingested so they can be flushed out

through urine

- Not so dangerous

http://www.youtube.com/watch?v=upH6wJx-oHA&safe=active

4 SUBCATEGORIES OF PESTICIDES:

1. INSECTICIDE:kills INSECTS

2.HERBICIDE:kills plants

3. FUNGICIDE:kills mould/fungi

4. BACTERICIDE:kills bacteria

OLDER VS NEWER PESTICIDES.

1. Older pesticides

•FAT-SOLUBLE

•When ingested by an organism, these

pesticides attach to fat cells.

•This was highly effective as they

PERMANENTLY remain in the organism.

BioaccumulationAlso known as

BIOAMPLIFICATION or

BIOMAGNIFICATION

A phenomenon in food

chains whereby FAT-

SOLUBLE PESTICIDES

build up in the fat cells

of consumers at higher

trophic levels.

Bioaccumulation and DDTDDT = Dichlorodiphenyltrichloroethane

FAT-SOLUBLE insecticide to

control insects that:

•Feed on agricultural crops

•Damage forests (ex: spruce

budworm)

•Carry diseases (ex: malaria)

It was VERY EFFECTIVE at killing pests

But there was an unknown effect ,it stayed in the

bodies of other organisms . . .

FIRST NOTICED EFFECTS:

•Egg shell thinning in top carnivore

birds, such as Bald Eagle

•Thin shells meant HIGH RATES of chick

mortality

It takes about 15y for DDT

to break down in the

environment.

What do we do?

•Ban DDT and other fat-soluble pesticides.

It is now banned in CANADA

and many parts of the world,

BUT SOME COUNTRIES are still

using it.

•Use water-soluble pesticides instead.

•Use sustainable alternatives to pesticides.

•CHEMICAL CONTROL

•BIOLOGICAL CONTROL

2 MAIN TYPES OF PEST

MANAGEMENT

Chemical ControlAlthough chemicals are highly effective,

there are several DISADVANTAGES to

using them, including:

•BIOACCUMULATION

•Not TARGET-SPECIFIC

•Not 100 % EFFECTIVE (some pests will

not be killed)

•Could lead to PESTICIDE RESISTANCE

Biological ControlsAlthough they are more TARGET-SPECIFIC,

there are several DISADVANTAGES including:

•Expensive

•Short-Term Effectiveness

•Organisms simply move to another area

Methods include using:

•NATURAL PREDATORS

•DISEASE ORGANISMS

•COMPETITORS

•PHEROMONES

Pesticide ResistanceSome pests are

naturally immune

to pesticides.

Once non-immune

pests are killed off,

the immune

PESTS are left to

reproduce a new

generation of

PESTICIDE

RESISTANT

PESTS.